Referring to FIG. 1, when harvesting crops with agricultural harvester combine 10, the crop being harvested is cut or collected as the combine traverses the field, by the head or header 12 mounted to the forward end of the combine 10. The header 12 feeds the crop into the feeder house 14 which carries the crop to the thresher, indicated generally by reference numeral 16 within the interior of the combine 10. The thresher 16 removes the grain from the plant material (e.g., the stalk, cob, pods or other plant material depending on the crop being harvested). The threshed grain then passes through sieves, indicated generally by reference numeral 18, which separate the grain from the unwanted plant debris. The unwanted plant debris is passed toward the back of the combine where it is discharged. The sieved “clean” grain is directed toward and is collected at the bottom of the clean grain elevator 22. The clean grain elevator 22 lifts the collected clean grain upward into a discharge area 24. An auger 26 within the discharge area 24 carries the grain into a holding tank or hopper 28. As the hopper 28 begins to fill, the grain is unloaded as needed by the unloading auger 30 into a waiting grain cart, wagon, truck or other transport (not shown).
Referring to FIGS. 1 and 2, the clean grain elevator 22 is disposed within a housing 32 and is comprised of a chain 34 which passes around upper and lower sprockets 36, 38. A plurality of equally spaced flights or paddles 40 are attached to the chain 34. As the chain 34 is rotated by the sprockets 36, 38 the paddles 40 scoop the grain being collected at the bottom of the elevator 32 and lift it upward toward the top of the elevator housing 32. As the paddles 40 pass over the upper sprocket 36, the grain is thrown into the discharge area 24 as illustrated in FIG. 2.
In many combines, a yield sensor 50 is positioned in the discharge area 24. While there are many types of yield sensors, a common yield sensor 50 includes an impact plate 52. The impact plate 52 is positioned so that when the grain is being thrown by the paddles 40 as the paddles 40 pass over the upper sprocket 36, the grain “impacts” the impact plate 52. The impact of the grain causes the impact plate 52 to displace which generates a signal. The signal generated due to the displacement of the plate 52 correlates to the amount of grain impacting the plate which correlates to yield. However, in operation of yield sensors for which a layer of grain imposes a centrifugal force on the yield sensor, empirical studies have shown that conventional paddles generate inconsistent signals at the yield sensor, particularly at low grain flows. Accordingly, there is a need for an improved paddle for clean grain elevator of a combine that will throw the grain in a manner so as to obtain a more accurate and consistent yield measurements.